The overall objective of this proposal is to improve the throughput capacity, material workflow and process efficiency, worker safety and sustainability, and to enhance water and utilities conservation in the cage wash area of Stanford University's core research animal facility (RAF). The existing cage wash system in RAF operates 10-12 hrs/day, 7 days a week, and accommodates a weekly throughput of ~35,000 rodent cages and approximately 80 nonhuman primate and large animal cages. With the addition of new and exciting research programs in regenerative medicine, optogenetics, cancer research, and biomedical engineering, including the addition of rodent behavioral testing core services and a rodent imaging core service, the animal census has grown by ~40% in the last 4 years. The replacement of the existing rack washers in RAF with more modern rack washers would increase the throughput by an estimated 40%, allow for optimal space use and work flow in the cage wash area, enhance worker safety and comfort, result in a cost savings on utilities, and greatly improve water conservation by a projected annual savings of ~5 million gallons of water, a precious resource in drought-prone California. The two new rack washers will allow the RAF, in the face of increasing demand, to maintain animal well-being and the cage sanitation process in compliance with the standards required by the Animal Welfare Act, the USDA, and the DHHS.